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B.3 direct addressing, Direct addressing – FUJITSU F2MCTM-16LX User Manual

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APPENDIX

B.3

Direct Addressing

An operand value, register, or address is specified explicitly in direct addressing mode.

Direct Addressing

Immediate addressing (#imm)

Specify an operand value explicitly (#imm4/ #imm8/ #imm16/ #imm32).

Figure B.3-1 Example of Immediate Addressing (#imm)

Register direct addressing

Specify a register explicitly as an operand. Table B.3-1 lists the registers that can be specified. Figure B.3-2

shows an example of register direct addressing.

MOVW A, #01212H (This instruction stores the operand value in A.)

Before execution

A 2 2 3 3 4 4 5 5

After execution

A 4 4 5 5 1 2 1 2

(Some instructions transfer AL to AH.)

Table B.3-1 Direct Addressing Registers

General-purpose register

Byte

R0, R1, R2, R3, R4, R5, R6, R7

Word

RW0, RW1, RW2, RW3, RW4, R5W, RW6,
RW7

Long word

RL0, RL1, RL2, RL3

Special-purpose register

Accumulator

A, AL

Pointer

SP *

Bank

PCB, DTB, USB, SSB, ADB

Page

DPR

Control

PS, CCR, RP, ILM

*: One of the user stack pointer (USP) and system stack pointer (SSP) is selected and used depending

on the value of the S flag bit in the condition code register (CCR). For branch instructions, the
program counter (PC) is not specified in an instruction operand but is specified implicitly.